Process of mercerizing.



UNiTnD STATES PATENT OFFICE.

HENRY EDlVARD AYKROYD, OF ILKLEY, AND PAUL KRAIS, OF BRADFORD, ENGLAND.

PROCESS OF MERCERIZING.

SPECIFICATION formingpart of Letters Patent No. 657,849, dated September 1 1, 1900. Application filed December 19, 1899- ri l 740,922. (specimens) To all whom it may concern:

Be it known that we, HENRY EDWARD AYK- ROYD, a subject of the Queen of Great Britain, residing at Ilkley, (whose post-office address is Glen Rosa, Ilkley,) and PAUL KRAIS, asub- ,ject of the Emperor of Germany, residing at Bradford, (whose post-office address is 14 Farucliffe road, Bradforch) in the county of York, England, have invented certain new and useful Improvements in Treating Cellulose Yarns and Fabrics, of which the following is a specification.

This invention has for its object a method of treating fibrous yarns and Woven or other fabrics of cellulose fiber, whereby they gain more or less the appearance of silk.

We wind the fiber or yarn or stretch the cloth on a frame, so that it cannot contract during the operation. We then immerse it in a solution of caustic soda, preferably of from to Twaddell and about 20 ce'nt-igrade, until it is thoroughly soaked, this operation usually taking about five minutes. In place of caustic soda we may use "caustic potash. The material is now taken out and mechanically dried that is not evaporated, but the surplus of the caustic-alkali solution separated from it by squeezing, by the action of a centrifugal machine or other means,

whereby the excess of liquoris separated from the cellulose without evaporation. It is now exposed to the vapors of boiling bisulfid of carbon for about ten minutes. It is not absolutely necessary to boil the bisulfid of carbon. The material can be exposed to an atmosphere charged with bisulfid of carbon by passing a jet of steam into a little of the latter placed below the fabric or in other Ways, or bisulfid of carbon in other attenuated forms could be used-such, for instance, as bisulfid of carbon mixed with benzene, tetrachlorid of carbon, alcohol, methylalcohol, acetone, naphtha, or other diluent, or even in some instances the undiluted bisulfid of carbon can be usedthe object being to expose every particle of the alkali-cellulose uniformly to the action of bisulfid of carbon. The thiocarbonate of cellulose thus formed is decomposed in any Well-known rnanner--such as, for instance, bybeing passed through a solu tion of ehlorid of ammonium or by being simply heated or Washed with a solution of common salt or sulfate of soda (Glauber salt) or any soluble acid or even by the simple application of heat to centigrade or upward. If it be now desired that the material which is of slightly-brownish tint should be made white, it can be bleached with any ordinary bleaching agent.

We claim as our invention- 1. The process of treating cellulose materials during the process of mercerization, which consists in immersing them in a stretched condition in caustic alkali, separating the surplus caustic liquor, exposing the treated fiber to the action of bisulfid of carbon and afterward decomposing the thiocarbonate of cellulose formed on the fiber, substantially as described.

2. The improvementin the process of mercerization, or making silk-like materials from fibrous cellulose, Which consists in partially converting the same during the process of mercerization and while in a stretched condition into cellulose thiocarbonate, and then decomposing the thiocarbonate, substantially as described.

3. The improvement in the process of mercerization, or making silklike materials, which consists in taking dry alkali-cellulose fiber While under process of mercerization and treating it with bisulfid of carbon in an attenuated form and decomposing the cellulose thiocarbonate thus formed, substantially as described.

In witness whereof we have hereunto signed our names, this 4th day of December, 1899, in the presence of two subscribing Witnesses.

HENRY EDWARD AYKROYD." PAUL KRAIS.

Witnesses:

HENRY KILLIoK, JAMES HEWORTH. 

